LOS ANGELES, California (CNN) -- Search warrants filed Thursday in court in Clark County, Nevada, and carried out at properties of Michael Jackson's doctor imply that investigators looking into his death believe the singer was a drug addict.

Dr. Conrad Murray was with Michael Jackson on the day that he died.

The warrants, signed by District Judge Timothy Williams and given to CNN by Las Vegas affiliate KTNV, say "there is probable cause to believe" that searches would uncover evidence at the Las Vegas home and office of Dr. Conrad Murray of excessive prescribing, prescribing to an addict, excess treatment or prescribing, unprofessional conduct, prescribing to or treating an addict and manslaughter.

They cite "probable cause to believe" that the premises contained "records, shipping orders, distribution lists, use records relating to the purchase, transfer ordering, delivery and storage of propofol (Diprivan)."

A source told CNN on Monday that the Texas-based cardiologist allegedly gave Jackson the anesthetic propofol -- commonly known by the brand name Diprivan -- in the 24 hours before he died.

A source involved in the investigation into Jackson's death has told CNN that investigators found numerous bottles of prescription drugs in his $100,000-a-month rented mansion in Holmby Hills, California. Watch report on the warrants »

The items taken from Murray's home included copies of his computer and cell phone hard drives. They were to be turned over to the Los Angeles Police Department, which is leading the investigation into Jackson's death last month at age 50.

Murray is the central focus of a federal investigation into the singer's death, a law enforcement official told CNN on Wednesday.

Authorities have subpoenaed the records of various doctors who have treated Jackson over the years, but "Dr. [Conrad] Murray is the only one we're looking at," the federal law enforcement official said.

Meanwhile, Murray failed to make a payment of $15,000 on his $1.65 million home in January and has racked up debt since.

If he does not make a payment by mid-August, he will lose his home to foreclosure, a spokeswoman confirmed.

"He was to be paid $150,000 a month by Michael Jackson," the spokeswoman said. "He was not [paid] by AEG, the tour promoter, or Jackson, for the two months he worked for them. So he's low on money."

Murray has been beset by financial difficulties since graduating from medical school.

He filed for Chapter 7 bankruptcy protection in 1992 and accumulated $44,663 in state tax liens in Arizona and California from 1993 until 2003, according to court documents.

He has also has been hit with several judgments related to unpaid bills, child support payments and defaults on education loans.

On Wednesday, CNN learned Murray was arrested on a charge of domestic violence disorderly conduct in Tucson, Arizona, in 1994.

Murray's then-girlfriend accused him of having an affair and threw something at him, Tucson law enforcement officials said. Murray allegedly pushed the woman down.

The doctor was acquitted five months after the incident.

Joe Jackson: Jackson had another son

In an interview with the Web site NewsOne, Jackson's father, Joe, said the singer had another son, a 25-year-old Norwegian performer, Omer Bhatti.

"Yes, I knew he had another son. Yes, I did," Joe Jackson said. "He looks like a Jackson, he acts like a Jackson, he can dance like a Jackson. This boy is a fantastic dancer. As a matter of fact, he teaches dancing."

At Jackson's memorial service this month, Bhatti was seated in the front row between the pop star's father and sister.

CNN has been unable to confirm the relationship. And Bhatti has told various media outlets that he and Jackson were close friends.

Battle brews over Jackson's will

Jackson's estate is worth at least $200 million and could amount to much more, an informed source told CNN on Wednesday.

Earlier this month, a Los Angeles Superior Court judge granted control of Jackson's assets to the executors of his will: John Branca, Jackson's longtime personal attorney, and John McClain, a music industry executive and longtime friend.

A third executor, accountant Barry Siegel, recused himself. Jackson's mother, Katherine, now wants the judge to install her in the open slot.

The judge has scheduled a hearing on Monday.

"The question is, will all this get resolved on Monday, when there is a hearing?" said CNN legal analyst Lisa Bloom. "Or will this blow up into a huge dispute between Katherine and the executors?"